Related Clues:

• Tight-lipped
• Muted
• Not open
• Opposite of 18-Across
• Isolated, with "off"
• Like diplomatic pouches
• Like Arbuckle's films
• Seal tightly
• Enclosed tightly
• Closed tightly
• Slammed, maybe
• Word with ''in,'' ''up'' or ''down''
• Unspeaking
• Early movie
• Z's